There are no current plans to change Romney's convention schedule, the officials said, emphasizing that no decisions had been made about a potential visit. Romney, who flew to Indiana to address the American Legion, was returning to Tampa Wednesday evening and will deliver his convention speech Thursday night.

Election 2012: A Look Back

But with rain beating down on New Orleans and flooding intensifying, eyes are turning to the battered Gulf Coast. Louisiana Gov. Bobby Jindal said Wednesday that officials might intentionally breach a levee in Plaquemines Parish to help deal with surging waters.

Romney's campaign is in close touch with governors in the region, particularly Jindal. Campaign officials have also been in touch with the American Red Cross and the National Weather Service.

Isaac Storms The Gulf Coast

The storm is diverting attention from the festivities in Tampa, where Republicans officially nominated Romney for president on Tuesday. Romney officials and convention organizers have been holding conference calls about the weather every few hours for the past several days as they consider whether or how to change plans.

Even if the convention schedule doesn't change again, officials are acutely aware that they might need to adjust the tone of each day's celebration. They have, for example, discussed potentially raising money for hurricane victims during the gathering. As a model, they are relying in part on the example 2008 presidential nominee John McCain set with his convention in St. Paul, Minn. Republicans delayed that convention as a hurricane threatened the Gulf. Romney already has delayed his convention because of Isaac, holding an abbreviated session Monday and moving many major speakers to other days.

Hurricane Isaac is a Category 1 storm — much weaker than the Category 5 Hurricane Katrina that devastated New Orleans almost exactly seven years ago. But its slow-moving rains are threatening people and livelihoods. On Wednesday, rescuers in boats and trucks plucked a handful of people who became stranded by floodwaters in thinly populated areas of southeast Louisiana. Authorities feared many more could need help after a night of slashing rain and fierce winds that knocked out power to more than 600,000 households and businesses.

Romney landed in Indianapolis on Wednesday afternoon to address the American Legion, where he'll focus on how the country can better help unemployed veterans find work. He's focusing on veterans' issues as McCain and former Secretary of State Condoleezza Rice plan to focus on defense and foreign policy in convention speeches Wednesday evening.

Romney had initially planned to appear in the convention hall via video from Indiana, speaking to attendees in conjunction with McCain. The campaign scrapped that plan Wednesday and Romney will instead return to Tampa. Officials wouldn't say if he planned to appear in person with McCain at the convention.

The newly minted nominee is set to deliver his address from the convention stage Thursday evening. Romney spokesman Kevin Madden said the speech would include some discussion of Romney's Mormon religion, a subject he hasn't frequently addressed on the campaign trail.

"This is a speech where he's going to talk a lot about what's informed his values, what's informed his outlook. Of course his faith is an important part of that," Madden said.